Narrative:

I was the copilot on flight from phx to tus. We were approaching the hold short line for runway 26L in phoenix, az. Tower told us to position and hold on runway 26L and said there was a B737 on a 5 mi final. I read back the position and hold clearance and we taxied into position on runway 26L and waited for an aircraft to clear the runway. After about 1 min we got an ECAM warning on our EFIS system telling us that we had a stuck microphone. Both the captain and I switched the transmitter selector to a different radio and now heard the controller telling the B737 to go around. We then found the hand microphone on the copilot side was shorting out and sticking. I called tower using my push to talk switch and we were cleared for takeoff. After landing in tus, the tower asked us to call phoenix tower. The captain called and explained the problem was caused by a faulty microphone. The airbus 320 has 2 hand mikes, 2 push to talk switches on the radio control panel, 2 push to talk switches on the respective control sticks. The only way to see if a transmission is taking place is after 1 min of continuous transmission you get an ECAM warning on EFIS.

Related reports:

Google
 

Original NASA ASRS Text

Title: AN A320 GND HOLDING ON THE RWY AT PHX EXPERIENCES A STUCK MIKE. A B737 ON FINAL HAS TO BE SENT AROUND.

Narrative: I WAS THE COPLT ON FLT FROM PHX TO TUS. WE WERE APCHING THE HOLD SHORT LINE FOR RWY 26L IN PHOENIX, AZ. TWR TOLD US TO POS AND HOLD ON RWY 26L AND SAID THERE WAS A B737 ON A 5 MI FINAL. I READ BACK THE POS AND HOLD CLRNC AND WE TAXIED INTO POS ON RWY 26L AND WAITED FOR AN ACFT TO CLR THE RWY. AFTER ABOUT 1 MIN WE GOT AN ECAM WARNING ON OUR EFIS SYS TELLING US THAT WE HAD A STUCK MIKE. BOTH THE CAPT AND I SWITCHED THE XMITTER SELECTOR TO A DIFFERENT RADIO AND NOW HEARD THE CTLR TELLING THE B737 TO GAR. WE THEN FOUND THE HAND MIKE ON THE COPLT SIDE WAS SHORTING OUT AND STICKING. I CALLED TWR USING MY PUSH TO TALK SWITCH AND WE WERE CLRED FOR TKOF. AFTER LNDG IN TUS, THE TWR ASKED US TO CALL PHOENIX TWR. THE CAPT CALLED AND EXPLAINED THE PROB WAS CAUSED BY A FAULTY MIKE. THE AIRBUS 320 HAS 2 HAND MIKES, 2 PUSH TO TALK SWITCHES ON THE RADIO CTL PANEL, 2 PUSH TO TALK SWITCHES ON THE RESPECTIVE CTL STICKS. THE ONLY WAY TO SEE IF A XMISSION IS TAKING PLACE IS AFTER 1 MIN OF CONTINUOUS XMISSION YOU GET AN ECAM WARNING ON EFIS.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.